Six months after a deadly shooting at a Quebec City mosque, its president's car was deliberately set afire, officials said on Wednesday.

"Another hateful act" targeted the mosque and its president Mohamed Labidi in addition to "a long series" of other incidents, the Islamic Cultural Center of Quebec said in a statement.

The fire was set on 6 August, but only made public on Wednesday in order to allow police to investigate.

Mosque officials and the mayor linked the fire to a 4 August announcement of the forthcoming opening of the city's first Muslim cemetery.

"It would be a strange coincidence" if the two were not somehow related, said Quebec City mayor Regis Labeaume.

Police are not ruling out any motive, whether it was a hate crime against Muslims or just a random act of vandalism, said police spokesman Jean-Francois Vezina.

Labeaume had championed the new Muslim cemetery as a sign of support for Quebec City's relatively small Muslim community after the slaying of six worshippers at the mosque by an avowed white supremacist in January.

Police identified the suspect as Alexandre Bissonnette, a French-Canadian. He was a student at Quebec's Laval University, a 10-minute walk from the mosque.

Bissonnette was charged with six counts of first-degree murder and five attempted murder charges. His trial is ongoing.

The "increase in hateful gestures" towards the Muslim community in Quebec City is "worrying," Labeaume said.

These incidents come as nationalist or right-wing extremists in the Canadian province have become more vocal against immigration and "radical Islam".

In June, a pig's severed head was left at the entrance of the mosque targeted by the lone gunman.

Police are investigating these incidents, but no suspects have been identified so far.

Amira Elghawaby, spokeswoman for the National Council of Canadian Muslims, told Middle East Eye in February that the Quebec mosque shooting was unprecedented.

“This incident, this attack, nothing like this has ever happened in this country before against any other group. This is historic,” she said.

“And if we don't act proactively to prevent anything like this from happening to any other community or us again, then we will have definitely failed.”

Bias attacks against Muslims have been on the rise in Canada.

In 2015, 159 hate crimes targeting Muslims were reported to police across Canada, up from 99 incidents the previous year, while hate crimes in general rose by five percent across the country in 2015, Statistics Canada said in June.